Category Archives: LEDs

October 25, 2011 — Strategies in Light, an annual tradeshow on high-brightness LEDs and lighting hosted by Strategies Unlimited and PennWell Corporation, will take place February 7-9, 2012 in Santa Clara, CA. New this year, the conference will include a full parallel track on LED manufacturing.

SIL 2011 hosted a half-day track on LED manufacturing, and attendees called for more information on the topic at SIL 2012. The HB LED industry is heading increasingly into high-volume manufacturing (HVM), bringing increased attention to fabrication issues and trends. LED equipment suppliers and traditional semiconductor tool makers are serving the LED industry. The trend is to move LEDs to larger wafer sizes for better economies of scale. Concurrent trends are pushing increased automation and improved yield and throughput. The LED Manufacturing Track is sponsored by SEMI.

The HB-LED market grew 108% in 2010, driven in large part by LED backlighting in LCDs (TVs, computers and laptops) and causing widespread industry scale-up. 2011 growth is forecast to be 10%, as LCD TV demand slows and an LED oversupply suppresses prices. Nevertheless, the HB LED market is forecast to grow another 45% by 2014 to $16.2 billion, driven by recovery in the backlight market and by the continuing adoption of LED lighting. The LED market is

October 25, 2011 – Marketwire — Bridgelux Inc., LED lighting developer and manufacturer, closed an additional $15 million in financing. The funds were needed to accelerate R&D and scaling of Bridgelux’s gallium nitride on silicon (GaN-on-Si) light-emitting diode (LED) chip technologies.

The oversubscribed financing round included existing financial and strategic investors: VantagePoint Capital Partners, DCM, El Dorado Ventures, Novus Energy Partners, IFA, Chrysalix, Harris & Harris Group, Craton Equity Partners, Jebsen Asset Management, and Passport Capital, among others. The company’s prior fundraising (series D) hit $50 million.

The goal is commercial-grade LEDs on silicon, commercialized in 2013, developed alongside Bridgelux’s GaN-on-sapphire arrays, said Bill Watkins, Bridgelux CEO. Bridgelux reported a new Lumens/W company record for Gan-on-Si LEDs in August 2011, claiming sapphire-like results.

The cost-reducing silicon-based technology could help the company take a larger market share of solid-state general lighting, which could grow from $3 billion in 2011 to more than $25 billion in 2015, Watkins said.

Bridgelux develops and manufactures solid state lighting (SSL). For more information about the company, please visit www.bridgelux.com.

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October 21, 2011 — Sapphire substrate maker Rubicon Technology Inc. (NASDAQ:RBCN) will transition to on-premise aluminum oxide processing to better control the quality of its sapphire wafers, and reduce manufacturing expenses while ensuring a steady supply of raw materials.

Rubicon’s customized in-house method converts raw aluminum oxide powder so it can be used in the Rubicon ES2 crystal growth process. The powder is formed into various shapes to optimize crucible space, enabling growth of larger crystals.

Large-diameter wafer transitions are occuring around the light-emitting diode (LED) industry, noted Raja Parvez, Rubicon president and CEO, who explained that the larger wafers can be as much as 3x thicker than 2" to 4" wafers, requiring more aluminum oxide. To date, Rubicon has successfully shipped more than 150,000 6" sapphire wafers.  

Advances in raw material handling combined with recent company-wide installation of enhancements to its proprietary crystal growth furnaces, Rubicon Furnace Version ES2-XLG3.0, delivers cost efficiencies for the production of large diameter sapphire. Rubicon

October 14, 2011 — Optogan opened its light-emitting diode (LED) production site in Landshut, Germany, bringing "future-oriented" industry to Bavaria, said the Minister of Economic Affairs of the German Federal State of Bavaria, Martin Zeil, who spoke at the opening.

Optogan expanded in Germany with the new site, located near to Munich Airport. A former Hitachi semiconductor fab, the site boasts a 4000m2 cleanroom. Up to 100 workers will staff the site. Initial capacity will exceed 1 billion chips/year. The site will be Optogan’s hub of international business, which is expanding from Europe to a global scale, explains Hans Peter Ehweiner, managing director of Optogan GmbH.

The Landshut LEDs will be used for lamps and luminaires in indoor, outdoor, and residential applications.

The Optogan Group develops and manufactures state-of-the-art chip technologies. Learn more at www.optogan.com.

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October 13, 2011 — Researchers from the Samsung Advanced Institute of Technology (SAIT) and the University of Cambridge created a full-color high-resolution 4" quantum dot light emitting diode (QD-LED) display using transfer printing (Nature Photonics, 2011).

Figure. Transfer printing for patterning quantum dots (QDs). (i) Modification of the donor surface with SAM, and spin-coating of QDs. (ii) Application of an elastomer stamp to the QD film with appropriate pressure. (iii) Peeling of the stamp, quickly, from the donor substrate. (iv) Contacting the inked stamp to the device stack, and slowly peeling back the stamp. (v)–(vii) Sequential transfer printing of green and blue QDs. b, Fluorescence micrograph of the transfer-printed RGB QD stripes onto the glass substrate, excited by 365 nm UV radiation.

The team began by modifying the donor substrate surface with a chemically bound self-assembled monolayer (SAM). Red-, green-, and blue-emissive quantum dots are printed via the same precise process at room temperature. Various substrates could be used, including flexible ITO/PEN. Future work will focus on scaling the printing process to industrial production without degrading resolution. Aligning the different color QD stripes over large-area may pose a challenge, notes Khashayar Ghaffarzadeh, technology analyst, IDTechEx.
 
QD-LEDs are electroluminescent colloidal quantum dots that can be printed in thin films to combine inorganic LEDs’ customizable, saturated, stable color and low-voltage performance with polymers’ solution processability, said Ghaffarzadeh.

Also read: Quantum dot OLEDs fabbed via spin coating

For QD-LEDs to work, the thin film transistors (TFTs) in the active-matrix backplane must supply a very stable current. New backplane technologies like metal oxides could replace amorphous silicon for this function. Researchers from the University of Cambridge have also demonstrated solution-processed high-performance metal-oxide TFTs (Nature Materials, 2011) with a <250°C annealing temperature.

The University of Cambridge will present at IDTechEx’s Printed Electronics USA. Printed Electronics USA 2011 will take place November 29-December 2 in Santa Clara, CA, with tours to local centers of excellence. Learn more at www.IDTechEx.com/peUSA.

References:
Full-colour quantum dot displays fabricated by transfer printing, Nature Photonics 5, 176-182, (2011). Low-temperature, high-performance solution-processed metal oxide thin-film transistors formed by a ‘sol-gel on chip’ process, Nature Materials 10, 45-50(2011).

IDTechEx provides custom consulting, research and advisory services in Printed Electronics, RFID, Photovoltaics, Energy Harvesting and Electric Vehicles. Learn more at www.IDTechEx.com/nano.

October 12, 2011 — SEMI’s annual semiconductor silicon shipment forecast provides an outlook for silicon demand for 2011-2013.

SEMI recorded that polished and epitaxial silicon shipments will hit 9,131 million square inches (MSI) in 2011, 9,529 MSI in 2012, and 9,995 MSI in 2013 (table). Silicon wafers are the basis of virtually all semiconductors and MEMS, and epi-wafers are the basis of products like LEDs.

While the market has currently softened, early-2011 momentum will carry the year’s semiconductor silicon sales to a higher total than 2010, said Stanley T. Myers, president and CEO of SEMI, noting the figures are an industry record. Growth will continue at "modest levels" through 2013.

Table. 2011 silicon forecast, total Si slices excluding non-polished. SOURCE: SEMI, October 2011.
  2009 2010 2011 2012 2013
Millions of square inches (MSI) 6,554 9,121 9,131 9,529 9,995
Annual growth (%)  -17 39 0 4 5

Also read SEMI’s report from August 2011, Silicon wafer shipments ride out Japan disaster

The data are inclusive of polished silicon wafers, including virgin test wafers, and epitaxial silicon wafers shipped by wafer manufacturers to semiconductor end-users.

SEMI is a global industry association serving the nano- and microelectronic manufacturing supply chains. For more information, visit www.semi.org.

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October 10, 2011 — Several speakers at the recent OLEDs World Summit 2011 (9/26-28 in San Francisco) discussed the appeal of organic light emitting diodes (OLEDs) for large-format image displays, rising in appeal over liquid-crystal displays (LCD).

James Lee, research fellow at LG Display, made the case for using soluble technology for OLED fabrication, a technology the company has been developing. Though there are remaining challenges that have to be addressed, e.g., soluble material performance, particularly for blue CIE Y, Lee noted that substantial cost reductions can be achieved using this technology because of the simple OLED device structure and the simple bill of materials (BOM) associated with OLED displays (OLED displays require no backlight, just one sheet polarizer, and no C/F) and the simple mura-free process LG Display is developing with a printing partner. The company is confident its printing partner will solve the mura-free printing challenge within the next two years. Still-to-be-addressed system requirements include low power consumption (compensation circuitry), continued cost reduction for competitiveness (e.g., going from FMM to FMM-free patterning technology) and design differentiation (e.g., face-seal encapsulation).

According to Lee, 2012 is the first year that OLED TVs will penetrate the premium TV market. LG sees the market share of LED TVs increasing dramatically from 32% to 93% as the price premium narrows down to 20% from 53% in three years. Volume production of OLED TVs is expected to occur in 2013. "The OLED TV market will start to grow substantially in 2015 once the price premium will be reached at 50% like LED TVs," said Lee.

John Richard, VP, DuPont Displays, spoke about the appeal of OLEDs for large-format image displays. They offer visually compelling images with high contrast, large color gamut and rapid response time, he explained. There are also equipment cost and design advantages because of their very thin format, improved power efficiency, and simple panel structure.

However, he noted that three barriers must be overcome to successfully produce OLED TV:

  1. Material performance has to meet the thresholds for TV,
  2. OLED material deposition waste must be significantly reduced, and
  3. OLED material application equipment must scale to the size and productivity of its LCD counterparts.

Continuing the discussion about using solution OLED fabrication, Richard detailed the key materials challenges that are holding up progress:

  1. Being able to coat the blanket layers,
  2. Being able to contain the printing inks in the active subpixel area,
  3. Keeping successive layers from mixing with each other,
  4. Being able to clean the coated materials before encapsulation/bonding,
  5. Being able to print at high speed without visual defects, and
  6. Keeping atmospheric conditions during printing/coating from degrading the organic materials.

To tackle the challenges, DuPont teamed up with Dainippon Screen (DNS) to address nozzle printing for solution OLED patterning. In 2008, the collaboration resulted in a Gen 4 production-scale printer installed for 730mm

October 7, 2011 — Revenues for high-brightness light emitting diodes (HB-LEDs) grew 108% to $11.2 billion in 2010, driven by applications in TV backlight units, according to a new market report by Strategies Unlimited. The party is quieting down though, as expanding supply and a slowdown in overall TV demand in 2011 pushed LED prices drastically lower.

Strategies Unlimited revised down its 2011 HB-LED revenue estimate to $12.3 billion. LED prices plummeted 20-40% recently, except for certain specialized applications. This industry correction will take weaker and/or newer LED manufacturers out of the market. Look for consolidation in China. Strong manufacturers with deep pockets to survive fluctuations will survive, Strategies Unlimited reports.

Revenue will peak in 2014, hitting $16.2 billion, before dropping off to $15.3 billion the next year. Once lighting takes over as the growth driver for HB-LED adoption, predicted to occur in 2015, revenues will again increase.

The LED price drop could lead to higher LED adoption, particularly in lighting, where ELDs are about 30% of the bill of materials (BOM). Strategies Unlimited reports that high-quality, large-volume 1W cool white packaged LEDs with delivery in September 2011 are being quoted around $0.65.

In other application sectors, LED revenues for signs were $1.1B in 2010, growing to about $1.6B in 2015. Signage overall will grow at 14% CAGR through 2015, with the vast majority coming from Chinese manufacturers.

LEDs for mobile devices — smartphones, tablet computers, notebooks — will experience declining revenues 2010-2015, despite fast-growing device adoption. Here, price suppression will help bring LED revenues down -4.1% compounded annually.

Figure. HB-LED market by revenue and year-over-year (YoY) growth rate 2010-2015. SOURCE: Strategies Unlimited.

Automotive applications brought in $1.1 billion in LED revenues for 2010, thanks to China-based growth. As China cools off in 2011 and the Japan tsunami disrupted supply chains, 2011 will see only 5% growth in this sector. Increased use of LEDs in daytime running lights and headlamps will fuel revenue growth for LEDs in exterior automotive lighting at 10%, compounded annually.  Falling prices and saturation of LEDs in instrument panels — reaching 90% in 2015 — will erode LED revenue for that segment by 2% over the period.

Strategies Unlimited released

October 6, 2011 — Thanks to MEMS, 3D packaging, LEDs, power devices, and other applications, thinned wafers will be the majority of wafers in the market by 2016, according to Yole D

October 6, 2011 — The Royal Swedish Academy of Sciences awarded this year’s Nobel Prize in Chemistry to Dan Shechtman, Technion – Israel Institute of Technology, Haifa, Israel, for the discovery of quasicrystals.

Quasicrystals reveal an atomic structure of regular patterns that never repeat. The quasicrystal formation has therefore been likened to aperiodic mosaics found in the medieval Islamic Alhambra Palace in Spain (detail pictured above) and the Darb-i Imam Shrine in Iran.

Shechtman discovered the solid-matter arrangement in April 1982, using an electron microscope. Until his research, all solid-matter atoms were believed to be packed inside crystals in symmetrical patterns that were repeated periodically. Scientists considered this repetition required in order to obtain a crystal.

Shechtman showed that the atoms in his crystal were packed in a pattern that followed mathematical rules but could not be repeated. The controversial findings led to Shechtman being asked to leave his research group. However, his battle eventually forced scientists to reconsider their conception of the very nature of matter.

ElectroIQ’s Debra Vogler recalls arranging Dr. Shechtman’s lecture at Watkins-Johnson Semiconductor Equipment Group on quasicrystals in 1997 in this blog.

Shechtman’s quasicrystals are now described by "the golden ratio;" the ratio of various distances between quasicrystal atoms is related to the golden mean.

Following Shechtman’s discovery, scientists have produced other kinds of quasicrystals in the lab and discovered naturally occurring quasicrystals in mineral samples from a Russian river. A Swedish company has also found quasicrystals in a certain form of steel, where the crystals reinforce the material like armor.

Scientists are currently experimenting with using quasicrystals in different products such as frying pans and diesel engines.

Dan Shechtman is an Israeli citizen born 1941 in Tel Aviv, Israel. He received a Ph.D. in 1972 from Technion – Israel Institute of Technology, Haifa, Israel. He is a Distinguished Professor, The Philip Tobias Chair, Technion – Israel Institute of Technology, Haifa, Israel. Learn more at http://materials.technion.ac.il/shechtman.html

The Prize amount is SEK 10 million.

Visit http://www.nobelprize.org/nobel_prizes/chemistry/laureates/2011/announcement.html for more information.

See information on the 2010 Nobel Prize in Physics, for graphene research and blogger Linda Rae’s post on the winners.